A middle-aged census worker hung naked from a tree in the woods of Kentucky, the word "FED" scrawled on his chest.

That image, of course, turned out to be too neat to be true: Census worker Bill Sparkman staged his suicide to look like a murder by some rural antigovernment extremist, so his family would benefit from his life insurance policies. But even before the police had begun investigating the incident, the scene prompted a wave of commentary about right-wing extremism, with one prominent blogger talking about the spectre of "Southern populist terrorism."

The rush to judgment was found mostly on partisan websites but also in mainstream media outlets, which some commenters say shows that paranoia about political insurrection and violence is no longer restricted to the fringes of American politics.

"It was a spooky scene and a bizarre episode ... but the way in which people rushed to assume it was [political murder] showed that they were so eager to connect the dots that they ran ahead of what the evidence was," says Jesse Walker, managing editor of the libertarian Reason magazine. "The takeaway from the Kentucky story is that the establishment is just as capable of making that mistake as the fringes."

The reaction was understandable, to an extent. Apart from the details of the scene itself, a Department of Homeland Security report earlier this year had warned of an increase in right-wing extremism, including radicalization of US soldiers.

But the politicization of Sparkman's death, some conservative bloggers say, points to a new willingness to not only sharply disagree with opponents, but also to paint political enemies with the worst of motives. "What's uniquely disgusting about stories like this is the eagerness ... to find an ideological motive with which to bludgeon one's opponents," wrote Allahpundit on the conservative blog, Hot Air, on Sept. 24.

Both liberal and more mainstream bloggers tried to blame conservative media figures such as Glenn Beck and Rush Limbaugh.

"This is the kind of violent event that emerges from a culture of paranoia and unsubstantiated attacks. Personalities like Glenn Beck have irresponsibly accused the government of running FEMA concentration camps, and constantly stoke the fear of 'the Feds' taking over," wrote Allison Kilkenny at the Huffington Post.

"[T]he most worrying possibility – that this is Southern populist terrorism, whipped up by the GOP and its Fox and talk radio cohorts – remains real," Andrew Sullivan, a blogger for the Atlantic, wrote in late September, adding, "We'll see."

However, Mr. Sullivan Tuesday pushed back against claims he had said Sparkman was murdered by "neo-confederate thugs," writing, "I clearly suspected foul play and believed it wasn't suicide, I drew no firm conclusions about the actual perpetrators of this act. In every post, I made sure readers knew that the investigation was ongoing and we did not yet know the full facts. And at every opportunity, this blog linked to stories pushing back against the idea that this was a murder."

Not that there aren't legitimate threats from America's extremist fringes, says Mr. Walker, the Reason editor. But "panicky centrists" haven't been able to draw a direct link between talk radio rhetoric and actual violence.

"[B]y giving serious attention to theories associated with the fringe right ... [they argue] Glenn Beck and other broadcasters are validating the grievances of potential killers, giving them the impression that they aren't alone," wrote Walker in October.

One problem with this assumption, Walker writes, is that "it ignores the autonomy of people on the fringe.... You can't reduce media effects to simple push-pull reactions."